Universal surge protector for notebook computers

ABSTRACT

A surge protector for portable personal computers, or notebooks, of the shunting type, employs two differently rated metal oxide varistors in a manner enabling operation with several differently rated AC power services. The surge protector is designed to provide an optimum effective clamping voltage with a low let-through voltage.

CROSS-REFERENCE TO RELATED ACTIONS

[0001] This application is a continuation of National filing of U.S.application Ser. No. 09/601,228, filed Sep. 15, 2000, entitled UniversalSurge Protector for Notebook Computers.

FIELD

[0002] The inventions presented herein relate to method and apparatusfor diverting of harmful electrical voltage and current disturbances onalternating current (“AC”) power lines supplying power to portablepersonal computers, hereinafter referred to as “notebook computers,” a“notebook” or “notebooks.”

BACKGROUND

[0003] Generally, manufacturers and/or re-sellers of notebook computerspowered by a 16 volt direct current (“dc”) battery, for example, makeavailable to their customers a power adapter to produce a 16 volt dcoutput from different rated alternating current (“AC”) power servicesavailable from public or private electric power utility companies. Forexample, a power adapter generates the 16 volt dc voltage to run anotebook from a 120 volt, 60 cycles per second (“cps”) power servicecommonly available throughout the United States at a wall mounted outletin most homes and places of business. In addition, the power adaptersimultaneously re-charges the notebook's battery. The power adaptersalso produce the required 16 volt dc voltage from AC power sources usedin other countries of the world including: A 100 VAC, 50 cps, ratedservice used in Japan; and a 240 volt 50 cps rated service used inEurope, Asia, the Middle East, South America and Africa.

[0004] It is known among manufacturers of notebooks to locate a poweradapter inside the housing of a notebook. For brevity the followingdiscussion is limited to power adapters which are external to thenotebook housing. The housing for an external power adapter is generallyrectangular in shape and about the size of a audio cassette tape.Characteristically power adapters include both AC and dc power cords.The dc power cord is anchored at one end to the power adapter and has afemale dc plug at a free end for mating with a male dc receptaclemounted in the notebook housing. The AC power cord is a removable,specialized, electrical extension cord. The AC power cord has a two wirefemale AC plug at one end for mating with a male AC receptacle mountedin the housing of the power adapter and a two wire male AC plug at itsother end for coupling to an AC power service at a standard female ACreceptacle, wall mounted, for example.

[0005] Detachable AC power cords are available from or through notebookmanufacturers. These AC power cords include the required male AC plugneeded to fit the unique configuration of a female AC power receptacleof the AC power utility of a given country or region of the world.Consequently, an international traveler is advised to bring as many ACpower cords having country specific AC plugs as required for mating withthe unique mating connector of each power utility encountered on amulti-country trip.

[0006] An additional consideration for notebook computer owners is anelectrical surge protector for notebooks to protect their notebooks fromharmful electrical disturbances such as voltage and current transientswhich can damage a notebook. A damaged notebook normally means the ownerlooses the use of the notebook for getting productive work done. Harmfulelectrical disturbances occur on AC power lines for several well-knownreasons including switching ON or OFF an electric motor or a circuitbreaker carrying large electrical currents. Lightening strikes of ACpower lines during electrical storms are another well-known cause forharmful electrical disturbances appearing on AC power lines.

[0007] Protection of notebooks from the foregoing and other harmfulelectrical disturbances is a concern to users of notebook computersregardless of the country or utility district in which a notebook isoperated. In the United States. Underwriters Laboratories (“UL”), anelectrical product safety standard setting and testing organization,provides criteria for evaluating the performance of surge protectorswhen coupled to a 120 VAC rated AC power service. Specifically the UL1449 standard sets forth: (1) a let-through voltage criteria and (2) aneffective clamping voltage criteria. Each test criteria is useful forevaluating the performance of surge protector equipment intended toguard notebook computers from harmful electrical AC line disturbances.

[0008] A main component of prior art surge protectors for use withnotebooks coupled to a 120 volt rated AC power service is a metal oxidevaristor (“MOV”) or other voltage and current diverting and absorbingsemiconductor devices, such as, transorbs and sidactors. A MOV is thediverting and absorbing semiconductor device used in the majority ofprior art surge protectors to protect notebooks from harmful electricaldisturbances. A typical prior art surge protector employs a single MOVin combination with a fuse to protect a notebook from harmful electricaldisturbances.

[0009] Therefore, a first aspect of the present surge protector is toimprove the performance of surge protectors for use with notebookcomputers by designing them to achieve an effective clamping voltage of330 volt, while coupled to an AC power service rated from about 100 toabout 120 volts, which is the best clamping voltage rating under the UL1449 standard.

[0010] Accordingly an important aspect of the present surge protector isto improve the level of protection for notebooks from harmful electricaldisturbances over that achieved by prior art surge protectors whilecoupled to AC power services rated from about 100 to about 120 VAC whichsubstantially achieves the UL 1449 standard 330 volt best clampingvoltage and a low let-through voltage.

[0011] Another significant aspect of the present surge protector is theuniversal ability to protect a notebook from harmful electricaldisturbances appearing on an AC power line in nearly every developedcountry and in many undeveloped countries, of the world.

[0012] Still another novel aspect of the present surge protector is thatit employs two, differently rated, MOVs for protecting a notebookwherein a first, higher rated MOV protects a notebook while the surgeprotector is coupled to a high rated 240 VAC power service and a second,lower rated MOV protects the notebook while the surge protector iscoupled to a lower rated AC power service of from about 100 to about 120VAC.

[0013] Yet another aspect of this surge protector is that it includes aswitch comprising a switching circuit which automatically connects alower rated MOV across an AC power line when the AC power line iscoupled to a lower rated AC power service and automatically disconnectsthe lower rated MOV from the AC power line when the AC power line iscoupled to a higher voltage service leaving the higher rated MOV toprotect a load, such as a notebook.

SUMMARY

[0014] The present surge protector overcomes the limitations of existingsurge protectors used with notebooks to the benefit of internationaltravelers who carry notebooks along with them into countries havingdifferent rated AC power utilities. As pointed out above, an importantaspect of the present surge protector is the ability to use a singlesurge protector unit to protect a notebook in multiple countries eachhaving differently rated AC power services or within one country havingtwo or more differently rated AC power services. Specifically thepresent surge protector is operable to protect notebooks when they arecoupled to either a high rated AC voltage source. such as 240 VAC. 50 or60 cps. or a low rated AC voltage source. such as a I 00 or 120 VAC. 50or 60 cps AC power service. The surge protector offers protection fornotebooks while coupled to AC power services rated from about 70 VAC toabout 290 VAC.

[0015] The ability to protect notebooks when coupled to variously ratedAC power sources is achieved by organizing the surge protector into twoparts or sections. A first section of the surge protector includes afirst MOV for protecting a notebook from electrical disturbancesappearing on an AC power line coupled to a 240 volt AC power service. Asecond section, coupled in parallel with the first section, includes asecond MOV for protecting a notebook from electrical disturbancesappearing on an AC power line coupled to an AC power service rated from100 to 120 VAC. Consequently, the single surge protector describedherein is useable, for example, successively in Japan, the United Statesand Canada which offer low AC power services rated at 100 and 120 VAC,respectively, and in various European, Asian. African and South Americancountries which offer high AC power services rated at 240 VAC.

[0016] Both sections of the present surge protector are automaticallyselected to protect a power adapter and associated notebook when the ACpower line is coupled to a low rated AC power source, for example, a 120VAC rated AC power service. Only the first section of the surgeprotector is selected to protect the power adapter and notebook when theAC power line is coupled to a high rated AC power service. for example,a 240 VAC rated power service. A switch within the second section of thesurge protector includes an electrical-mechanical relay whichautomatically connects the second MOV across an AC power line when theline is coupled to a low rated AC power service and automaticallydisconnects the MOV from the AC power line when the line is coupled to ahigh rated AC power service.

[0017] The two MOVs relay and other electrical components of the surgeprotector are mounted on a printed circuit board (“PCB”) and are coupledto one another by conductive tracings on the PCB. The particulars of thesurge protector circuits are given below.

[0018] The surge protector disclosed herein is contained in a smallhousing large enough to hold the above-described PCB and all thecomponents carried by the PCB further including a male AC receptacle formating with a female AC plug at one end of an AC power cord. Undernormal operating conditions the housing is not noticeably warm to thetouch when the surge protector is coupled to AC power services ratedform 100 to 240 VAC.

THE DRAWINGS

[0019] The foregoing and other aspects of the disclosed surge protectorwill be apparent from a reading of the specification with reference tothe drawings which are:

[0020]FIG. 1 is a schematic diagram of a portable personal computer, ornotebook, showing the disclosed AC to dc voltage converter system,including a power adapter and a surge protector, ready to be coupled toa notebook and an AC power cord ready to be coupled to a wall mounted,female AC receptacle, representative of an AC power service.

[0021]FIG. 2 is an electrical circuit of a two part, or section,universal surge protector for protecting a notebook from electricaldisturbances associated with power lines coupled to differently rated ACpower services.

[0022]FIG. 3 is a circuit diagram of a switching circuit comprising theswitch used in the second section of the two part surge protector ofFIGS. 1 and 2 to connect and disconnect the second MOV to an AC powerline.

DETAILED DESCRIPTION

[0023] With reference to FIG. 1, the universal power surge protector 11,the power adapter 12 and the AC power cord 13 comprise an AC to dcvoltage converter system 14 for supplying a dc voltage to notebookcomputer 16 generated from an AC power source represented by the wallmounted female receptacle 17. The notebook 16 is representative ofpresent day notebooks available from several manufacturers for example:IBM®, Compaq®, Dells®, Hewlett-Packard® and Apples® Computer and manyothers. Certain currently marketed notebooks are designed for portableoperation from a dc 16 volt battery, for example, stored inside (andoutside) the computer housing or are designed for a tethered, stationaryoperation from a dc 16 volt output, for example, generated by a poweradapter from an AC power service available, by means of the proper ACpower cord, at the wall mounted female receptacle 17.

[0024] A power adapter, typically includes a switching power supply thatproduces a fixed dc voltage output, 16 volts, for example, from severaldifferently rated AC power services including those rated at 100, 120,208 and 240 VAC, at 50 or 60 cps. The operation and design of switchingpower supplies used by power adapters intended for use with notebooksare well understood in the art. Detailed information on the design andoperation of switching power supplies is available in data sheets andother product information obtainable from the above-identified notebookmanufacturers or their re-sellers, the disclosures of which are herebyincorporated by reference.

[0025] Power adapter 12 includes a dc output cord 18 permanentlyconnected at one end to a printed circuit board inside the power adapterhousing and connected at a free end to a dc female plug 19 for matingwith a recessed male dc receptacle 21 mounted within the housing of thenotebook. A recessed two pin AC male receptacle 22 is mounted in thepower adapter housing for coupling directly to an AC power line via anAC power cord 13 or through the surge protector 11 and its AC power cord23.

[0026] The AC power cord 23 of the surge protector includes a female ACplug 24 at one end for mating with the male AC receptacle 22 of thepower adapter. The other end of cord 23 is coupled to a printed circuitboard (“PCB”) within the surge protector housing. The surge protectoralso includes a two pin male AC receptacle 26 mounted within itshousing. AC power cord 13 includes an AC female plug 27 at one end formating with either the male AC receptacle 26 of the surge protector orthe male AC receptacle 22 of the power adapter 12. The male AC plug 28at the other end of cord 13 is configured to mate with a United Statesstandard female AC power line receptacle 17, shown mounted in a wall ofa room within an office building or home for example. Of course, a powercord 13 must include an appropriately configured male plug 28 for matingwith the specific standard design of an AC power line receptacleemployed in each country, or AC power service region, within which theuser intends to use a notebook computer.

[0027] It should be apparent that female AC receptacles 22 and 26mounted in the housings of the power adapter and surge protectorrespectively, are identical and that the female AC plug 24 at the freeend of cord 23 is identical to female AC plug 27 at one end of AC powercord 13. Consequently, a power adapter can be coupled directly to an ACpower source by power cord 13 when a surge protector is not available toprotect a notebook from harmful electrical disturbances.

[0028] As stated above the surge protector includes the two sectionsshown in FIG. 2. The first section of the surge protector includes aslow acting fuse 31 and a first high voltage MOV 32 coupled in seriesand in parallel, respectively with the line 33 and neutral 34 sides ofan AC power line. Slow acting fuse 31 protects the notebook the poweradapter, and the surge protector, in particular MOV 32, from a sustainedover current condition on AC power line 33 created, for example, by ashort circuit occurring at any of the foregoing three devices. Fuse 31protects the three devices by changing from an electrical conductor toan open circuit to disconnect and, thereby electrically isolate thenotebook, power adapter and the surge protector from the AC power lineunder a short circuit condition existing in one of the three devices.

[0029] MOV 32 protects the power adapter and notebook against electricalvoltage disturbances by diverting disturbances from the devices and byabsorbing energy associated with the disturbances that, for example,exceed the maximum allowable voltage rating of MOV 32, which is 300 VAC.Absent large AC line disturbances, the impedance of MOV 32 is in themegohm range which effectively appears as an open circuit between theline 33 and neutral 34 sides of an AC power line coupled to a 240 VACrated AC power service. MOV 32 switches to low impedance levels inresponse to large voltage disturbances appearing across the line 33 andneutral 34 sides of the AC power line. At the low impedance levels, MOV32 diverts the electrical disturbances away from a notebook 16 and poweradapter 12 and absorbs a portion of the energy associated with thedisturbance.

[0030] The second section of surge protector 11 includes thermal fuse 36and a second, lower rated MOV 41. Fuse 36 is selected for specificationswhich are compatible with MOV 41 in order to disconnect the surgeprotector, power adapter and notebook from the AC power line in theevent MOV 41 goes into a thermal run-a-way condition in response to asignificant sustained electrical disturbance.

[0031] The second section of the surge protector also includes aswitching circuit 37 for adding or connecting and removing ordisconnecting MOV 41 across the line 33 and neutral 34 sides of the ACpower line. The switching circuit includes an electro-mechanical relay38 which has a coil and a moveable conductive arm. The moveable arm isin an open circuit position when the relay coil is not energized and isin a closed circuit position when the coil is energized. Consequently,MOV 41 is coupled across the line 33 and neutral 34 sides of an AC powerline when the relay coil of relay 38 is energized, and is disconnectedfrom the AC power line when the relay coil of relay 38 is not energized.The switching circuit 37 energizes the relay coil to couple MOV 41across the AC power line while the AC power line is coupled to a 100 to120 VAC rated power service. The switching circuit prevents, that is,inhibits, the energizing of the relay coil of relay 38 while the ACpower line is coupled to a 240 VAC rated AC power service.

[0032] Turning to FIG. 3, MOV 41 is coupled between the line 33 andneutral 34 sides of an AC power line when the moveable contact switcharm 39 of relay 38 is at the closed circuit arm position represented bysolid line 39. The relay arm is at the closed circuit position while thecoil 40 of relay 38 is energized from a 100 to a 120 VAC rated AC powerservice. The moveable contact arm moves to and stays at the closedcircuit position 39 while transistor 44 is turned ON, enabling currentto flow through relay coil 40. While transistor 44 is OFF, no currentflows through relay coil 40 and the relay arm moves to its open circuitposition represented by relay arm 39 A, shown with a dashed line. Witharm 39 at the open circuit position MOV 41 is disconnected from acrossthe AC power line.

[0033] Relay coil 40 is automatically energized by transistor 44 whenthe surge protect is coupled to an AC power service rated from 100 to120 VAC. Transistor 44 is prevented from being turned ON by transistor43 when the surge protector is coupled to an AC rated power servicerated at 240 VAC.

[0034] The switching of transistor 44 ON and OFF occurs as follows. Thecollector electrodes of transistors 43 and 44 are coupled to the dcvoltage on the first dc bus or rail 42. The rail voltage is,substantially a steady state voltage to which capacitor C1 is charged bydiode 54, a half wave voltage rectifier coupled between the line 33 andneutral 34 sides of the AC power line by resistors R1 and R2 andcapacitor C1. The voltage on rail 42 is coupled to the collector oftransistor 44 through relay coil 40 and is coupled to the collector oftransistor 43 through resistor R6. The emitter electrodes of transistors43 and 44 are at a voltage potential slightly above that of the neutralside 34 of the AC power line to which the emitter of both transistorsare coupled through resistor R7.

[0035] The base electrodes of transistors 43 and 44 are coupled to asecond dc rail 46. The voltage of rail 46 is substantially, the steadystate voltage to which capacitor C2 is charged by half wave voltagerectifier diode 53 coupled between the line 33 and neutral 34 sides ofthe AC power line, by resistor R3 and capacitor C2 and by resistors R3,R4, R5, R8 and R9. Resistors R4 and R5 establish a fixed bias to thecathode of zener diode 49 and resistors R7 and R8 establish a fixed biasto the cathode of zener diode 51.

[0036] The automatic switch or switching circuit 37 operates as followswhen coupled to a 100 to 120 VAC rated power service: at 100 or 120 VAC,the dc potential on rail 46 is not adequate to bias the base oftransistor 43 through zener diode 49 to turn ON transistor 43. However,the dc potential on rail 46 is adequate to bias the base of transistor44 through zener diode 51 to turn transistor 44 ON. With transistor 44ON, current flows through the relay coil 40 causing the relay arm 39 tomove from its normally open circuit position represented by arm 39A tothe closed circuit position represented by arm 39. Upon arm 39 moving toits closed circuit position. MOV 41 is connected across the line 33 andneutral 34 sides of the AC power line to protect the load 35 fromharmful electrical disturbances as long as the AC power line is coupledto a 100 to 120 VAC rated AC power service. Typically, load 35 comprisesa power adapter 12 coupled to a notebook 16 or another load type.

[0037] Energizing relay coil 40 to connect MOV 41 across the load 35when the surge protector is coupled to a 100 to 120 VAC rated AC powerservice is preferred to energizing coil 40 when the surge protector iscoupled to a 240 VAC rated power service. The reason is that the 240 VACapproach results in an inefficient use of energy and makes it moredifficult to dissipate heat generated in the electrical components ofthe surge protector.

[0038] The automatic switching circuit or switch 37 operates as followswhen coupled to a 240 VAC rated AC power service: the dc potential onrail 46 is adequate to bias the base electrodes of both transistors 43and 44 through the above noted resistors and zener diodes to turn ONboth of the transistors. However, transistor 43 is turned ON first intime and, once ON, prevents or disables transistor 44 from turning ON.Transistor 43 is turned ON before transistor 44 because the timerequired to charge capacitor C3 to the voltage level at which zenerdiode 51 conducts, turning ON transistor 44, is longer than the timerequired for zener diode 49 to conduct and bias ON transistor 43. Withtransistor 43 turned ON and transistor 44 OFF, the potential at thecollector of transistor 43 is only slightly above that of neutral 34.This low voltage is coupled from the collector of transistor 43 throughdiode 52 and resistor R10 to the cathode of zener diode 51 preventingthe zener diode from conducting and turning transistor 44 ON. Withtransistor 43 ON transistor 44 stays OFF and no current flows throughrelax coil 40 causing the relay arm to remain at the open circuitposition represented by relay arm 39 A. Consequently MOV 41 is notconnected across the line 33 and neutral sides 34 of the AC power line.At this time MOV 32 in the first section of the surge protector protectsthe notebook by diverting harmful electrical disturbances from anotebook and absorbing portions of the energy of the disturbance.

[0039] In one embodiment resistor R2 and capacitor C1 are implemented ina three level ladder network with the capacitance of capacitor C1comprising the combined capacitance of three series connectedcapacitors. The resistance of resistor R2 is the combined resistance ofthree series connected resistors. Each end of the three resistors andthree capacitors are electrically coupled together to form the laddernetwork. The ladder network enables the voltage drop across each of thecapacitors to be evenly distributed making the voltage on rail 42 morestable.

[0040] Also, in the foregoing embodiment, resistors R1, R3 and R6 areeach implemented as three separate series connected resistors. The useof multiple series resistors in place of one enables I²R producing heatcreated in the resistors while coupled to an AC power service to bedissipated over a larger resistor surface area and over a wider area onthe PCB carrying the resistor and other circuit components of surgeprotector 12.

[0041] The division of the specific identified resistors of FIG. 3 intoseparate resistors increases the total resistance surface area fordissipating heat. Locating the multiple resistors at spaced locationsover the surface of the PCB avoids hot spots and helps lower thetemperature on the outside of the surge protector housing. The outsidesurface temperature of the surge protector housing is near that of theambient temperature when the surge protector is coupled form a AC powerservice rated from about 100 to about 240 VAC.

[0042] The surge protector, while coupled to a 120 VAC rated powerservice achieved an effective clamping voltage of 330 volts which is theUL 1449 standard best rating when tested with a 6000 V. 500 amp, 100kHz. Catagory A combined surge, defined by American National StandardsInstitute (“ANSI”) procedure C62.41. In addition the present surgeprotector achieved a let-through voltage of 161 VAC when subjected to a6000 V. 200 amp 100 kHz. Category A ringwave test. The let-throughvoltage is the difference between the clamping voltage and the standardpeak voltage of 169 for a 120 VAC rated power service.

[0043] The values of the resistors and capacitors and the identity ofthe transistors and the MOVs employed in surge protector 12 are listedin TABLE 1 below. Light emitting diode (“LED”) 60 shown in FIG. 3 emitsa green light whenever the surge protector is coupled to an AC powerservice to indicate that it is available for protecting against harmfuldisturbances on the AC power line. TABLE A Component Type/Rating FUSE 31MINI, UL. CA 4 A/250 V FUSE 36 Thermal 4 A/100° C. 520-0005 MOV 32ERZV14D471 125 J, 300 Vrms MOV 41 ERZV20D201 100 J, 130 Vrms Diodes 52,53 and 54 IA, 1000 V, SMA Zener 6.8 V, 225 MW Diode 49 SMD Zener Diode51 9.1 V, 225 W SMD Capacitor C1 AL, ELECT, 85 c (a) 10 uf, 100 V (b) 10uf, 100 V (c) 10 uf, 100 V Capacitor C2 10 uf, 100 V AL, ELECT, 85 cCapacitor C3 22 uf, 25 V C 6 − 3 × 4 − 5 Relay 38 48 Vdc Coil 120 V/10 ATransistor 43 MMBTA42LTI Motorola Transistor 44 FMMT458 Zetex LED 60Green R/A PCMNT R1 Resistor a 1.2 kΩ 1 W, 5% RC2512 b ″ c ″ Σ = 3.6 kΩR2 a 470 kΩ, {fraction (1/8 )}W, 5%, RC1206 b ″ c ″ Σ = 1.41 MΩ R3 a 10kΩ, 5%, 1W, RAD, RES, MOF b ″ c ″ Σ = 30 kΩ R4 30 kΩ, {fraction (1/4)}W, 5% RC2010 R5 7.5 kΩ, {fraction (1/8 )}W, 5% R6 a 56 kΩ, 1 W, 5%,RC2512 b ″ c ″ R7 56 Ω, {fraction (1/8 )}W, 5% RC 1206 R8 110 kΩ,{fraction (1/8 )}W, 5% RC 1206 R9 68 kΩ, {fraction (1/8 )}W, 5% RC1206R10 2.7 kΩ, {fraction (1/8 )}W, 5% RC1206

What I claim is:
 1. A universal surge protector for protecting aportable notebook computer (“notebook”) and an associated power adapterfrom harmful electrical disturbances occurring on an alternating current(“AC”) power line when the notebook is powered by a direct current(“dc”) battery voltage generated by a power adapter while coupled to anAC power service over the line and neutral sides of an AC power line.the surge protector comprising in combination a higher rated voltage andcurrent diverting and absorbing semiconductor device (“diverting andabsorbing device”) coupled across the line and neutral sides of an ACpower line for protecting a notebook and a power adapter from harmfulelectrical disturbances while the surge protector is coupled to a higherrated AC power service by an AC power line, a lower rated diverting andabsorbing device for diverting harmful electrical disturbances from anotebook and a power adapter and a switch for coupling the lower rateddiverting and absorbing device across the line and neutral sides on anAC power line in parallel with the higher rated diverting and absorbingdevice for protecting a notebook and power adapter from harmfulelectrical disturbances while the surge protector is coupled to a lowerrated AC power service by an AC power line.
 2. The surge protector ofclaim 1 wherein the higher and lower diverting and absorbing devicesinclude metal oxide varistors (“MOVs”).
 3. The surge protector of claim1 wherein the diverting and absorbing devices include transorbs.
 4. Thesurge protector of claim 1 wherein the diverting and absorbing devicesinclude sidactors.
 5. The surge protector of claim 1 wherein the switchcouples the lower rated diverting and absorbing device across an ACpower line while the AC power line is coupled to a lower rated AC powersource and de-couples the lower rated diverting and absorbing devicefrom across the AC power line while the AC power line is coupled to ahigher rated AC power service.
 6. The surge protector of claim 5 whereinthe switch includes a switching circuit responsive to voltages of alower rated AC power service to couple the lower rated diverting andabsorbing device across an AC power line and responsive to voltages of ahigher rated AC power service to de-couple the lower rated diverting andabsorbing device from across an AC power line.
 7. The surge protector ofclaim 1 wherein the lower rated diverting and absorbing device protectsthe notebook and power adapter from harmful electrical disturbanceswhile coupled to an AC power service rated from about 100 to about 120VAC.
 8. The surge protector of claim 1 wherein the lower rated absorbingand diverting device is coupled between the lower rated diverting andabsorbing device and a protected notebook and power adapter.
 9. Thesurge protector of claim 1 wherein the lower rated absorbing anddiverting device is coupled between the higher rated diverting andabsorbing device and a protected notebook and a power adapter.
 10. Thesurge protector of claim 1 wherein the switch includes anelectro-mechanical relay including a moveable conductive contact havinga closed circuit position for coupling the lower rated diverting andabsorbing device across the line and neutral sides of an AC power linewhile coupled to a low rated AC power service for enabling the lowerrated and the higher rated diverting and absorbing devices to divertharmful electrical disturbances away from a notebook and power adapter.11. The surge protector of claim 1 wherein the switch includes anelectro-mechanical relay including a moveable conductive contact havingan open circuit position for de-coupling the lower rated diverting andabsorbing device from across the line and neutral sides of an AC powerline when coupled to a high rated AC power service leaving the highrated diverting and absorbing device to divert harmful electricaldisturbances away from a notebook and power adapter.
 12. The surgeprotector of claim 1 wherein the switch includes an electro-mechanicalrelay having a moveable conductive portion having a closed circuitswitch position for coupling the lower rated diverting and absorbingdevice across the line and neutral sides of an AC power line for thehigh and low rated diverting and absorbing devices to divert harmfulelectrical disturbances away from a notebook and power adapter while thesurge protector is coupled to a low rated AC power service and the relayhaving a moveable conductive portion having an open circuit position fordecoupling the lower rated diverting and absorbing device from acrossthe line and neutral sides of an AC power for the high rated divertingand absorbing device to divert harmful electrical disturbances away forma notebook and power adapter while the surge protector is coupled tohigh rated AC power service.
 13. The surge protector of claim 12 whereinthe switch further includes a first transistor coupled to the relay forswitching the moveable conductive portion of the relay to its closedcircuit position when the first transistor is turned ON when the surgeprotector is coupled to a low rated AC power service and for switchingthe moveable conductive portion of the relay to its open circuitposition when the first transistor is turned OFF when the surgeprotector is coupled to a high rated AC power service.
 14. The surgeprotector of claim 13 wherein the switch further includes a secondtransistor coupled to the first transistor for preventing the firsttransistor from turning ON to move the conductive portion of the relayto its closed circuit position when the surge protector is coupled overan AC power line to the high rated AC power service.
 15. A universalsurge protector for the protection of notebook computers and associatedpower adapters from harmful electrical disturbances comprising incombination a first MOV having a clamping voltage at about 775 VAC andan energy absorption rating at about 125 joules. a second MOV having aclamping voltage at about 330 VAC and an energy absorption rating atabout 100 joules and a switching circuit including an electricallyoperated switch for coupling the second MOV across an AC power line inparallel with the first MOV while an AC power line is coupled to an ACpower service rated from about 100 VAC to about 120 VAC and forde-coupling the second MOV from an AC power line while an AC power lineis coupled to an AC power service rated from about 100 to about 120 VAC,the effective clamping voltage of the surge protector while the firstand second MOVs are coupled to an AC power service rated from 100 to 120VAC, being at about 300 VAC and the let-through voltage of the surgeprotector being at about 131 VAC when the surge protector is subjectedto a 6000 VAC, 500 amp, 100 kHz category B combination surge.
 16. Auniversal surge protector for protecting a battery powered notebookcomputer and an associated power adapter from harmful electricaldisturbances occurring on an AC power line while the notebook is poweredby a dc voltage generated by a power adapter coupled to an AC powersource over the line and neutral sides of an AC power line, the surgeprotector comprising in combination a high voltage section for couplingto the line and neutral sides of an AC power line and including a highvoltage rated MOV fixedly coupled across line and neutral for divertingharmful electrical disturbances away from a notebook and power adapterthrough the high voltage rated MOV when an AC power line is coupled to ahigh rated AC power service over an AC power line and a low voltagesection for coupling to the line and neutral sides of an AC power lineincluding a low voltage rated MOV and a switch for coupling the lowvoltage rated MOV in parallel pith the high voltage rated MOV fordiverting harmful electrical disturbances away from a notebook and poweradapter through the high and low voltage MOVs while the surge protectoris coupled to a lower rated AC power service and for de-coupling the lowvoltage rated MOV from an AC power line when the surge protector iscoupled to a high voltage rated AC power service.
 17. The surgeprotector of claim 16 wherein the first section further includes a slowacting fuse coupled to the line side of an AC power line for protectingthe notebook, power adapter and surge protector form a short circuitoccurring across an AC power line while the line is coupled to an ACpower service.
 18. The surge protector of claim 16 wherein the secondsection further includes a thermal fuse coupled to the line side of anAC power line for protecting a notebook and power adapter from a thermalrun-away circuit occurring at the low voltage MOV.